Rock-drill



`2 sheets-sheen 1.

(No Model.)

N. MILLER 8u J. RITGHIB.

ROCK DRILL.

Patented J 1m31 r w. ialidi nhogmpwr, wmmgm n. cA

(No Model.) 2 Sheets-Sheet 2.

N. MILLER 8v J. RITGHIE.

ROCK DRILL.

No. 387,096. Patented July 31, 1888..

UNITED STATES PATENT OEEICE.`

NATHANIEL MILLER AND JOHN RITCHIE, OF W'HAT CHEER, IOWA.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No` 387,096, dated July 31,1888.

Application tiled February 14, 1888. Serial No. 263,991. (No model.)

To @ZZ whoml t may concern.-

Beit known that we, NATHANIEL MILLER and JOHN RITOHIE, citizens of theUnited States, residing at Vhat Cheer, in the county of Keokuk and Stateof Iowa, have invented new and useful Improvementsin Rock-Drills, ofwhich the following is a specification.

Our invention relates to improvements in rock-drills, especially such asare adapted for soft coal and other similar materials; and it consistsin the construction and novel combination of parts hereinafterdescribed, illustrated in the drawings, and pointed out in the appendedclaims.

In the drawings, Figure l is a plan View of drill mechanism embodyingthe invention. Fig. 2 is a view of one side of the same. Fig. 3 is aview of the opposite side thereof. Fig. 4 is a plan view ofthe grip-armdetached. Fig. 5 is a transverse section of the feed-screw with thegear-wheel thereon. Fig. Gis a rear view, partly in section.

In the drawings, A designates the grip-arm, to which the drillingmechanism is attached, provided with the two boltAopenings a a', for theattachment of the bracket B. The said bracket is composed of thebase-plate b and the side plates, b b', having the downwardlyinclinedbearing-notches Z)2 b2 in their edges for the feed-screwbox bearings.

b4 is the central boltopening in the baseplate b, which opening issurrounded by the square flange b5, to receive the head b of the boltbl. By means of the bolt-head resting and fitting within said ange, thebolt cannot turn while the bracket is being tightened to thel grip-arm.This prevents a loose bracket, which is apt to turn slightly toward thehandle when operating the machine, and, the drill also being similarlyturned, the drill-hole will not be straight, and will cause the succeeding drill to bind therein.

C is the feed screw or sleeve, internally threaded in the usual manner,and made in two parts suitably secured together, as shown.

c c are the trunnions of the said sleeve,which trunnions rest in thebearings 12262. The trunnion c is extended beyond its bearing andsquared, as at c?, the squared portion being separated from the bearingby the collar c3. The said squared portion passes through an opening inthe arm D, which is secured in place by a pin or bolt passing through anopening in the squared portion outside of said arm. The arm D has at itsfree end a transverse bearingsleeve, d, for the drive'shal't E, rotatedby mechanism, (not showm) and having on its inner end the bevelgear-wheel e.

F is the feedscrew, having on its end the drillf, and liattened equallyat ff at diametrically-opposite points, as shown.

G is a bevel gear-wheel, having a central opening that lits accuratelyupon the feedscrew, having correspondingly-tlattened surfaces, so thatone will not turn without the other. The said gearwheel meshes with andis rotated by the gearwvheel e.

H represents a pair of steel pins adapted to be inserted into anyopposite ones of the series of openings g g in the side plates of thebracket, one pin passing under the feed-screw sleeve and the other underthe arm D. These openings are made near the front edge ot the side plateadjacent to said arm and near the rear edge of the opposite side plate,so that when the pins are put in place through corresponding openings inthe plates the same will support the :feed-screw sleeve and arm D at anydesired adjustment, either in a horizontal or in an inclined position.

The rotation of the wheel G by turning the feed screw causes the same totravel forward in the sleeve and carry the drill forward, and as itconforms to and fits over the said screw the latter can easily travelthrough it.

By making the arm D detachable from the trunnion of the feed-screwsleeve, instead of integral therewith, as is usually the case, a greatsaving of expense is obtained, for the said arm breaks frequently,rendering it necessary to get an entirely new sleeve, whereas thedetachable arm can be quickly and easily replaced.

The object of making the feedscrew flat 0n` two sides is to preventloose motion thereon of the gear-wheel G, as will frequently happen witha slotted feedscrew and key, in which the key wears and turns laterallyin the slot in a short time, allowing the gear-wheel G to assume anon-rectangular position on the feedscrew and cut the corners from thethreads of the same. This of course causes ragged threads that cut thethreads of the sleeve.

When the drill strikes a bed or layer of sulphur, which is much harderthan the soft coal the machine is intended for, the drill would becomedepressed but for the support given it by the steel pin, and the holewould be drilled out of alignment.

By using the two openings in the grip-arm the tirst and second drills,which are used more and Wear' faster than the third drill, may beadvanced when worn, so as to permit the third drill when inserted tomake the hole deep enough.

Having described our inventiomwe claim-4 l. In a rock-drill, thecombination of the bracket having the bearingnotches, the feedscrewsleeve having the trunnions in said notches, and the arm D, detaehablysecured to the extended squared end of one ofthe trunnions having thesleeve for the drive shaft, substantially as specified.

2. In a. rock-drill, the combination of the grip-arm, the bracketpivoted thereon, the feedsorew sleeve having the trunnions journaled inthe bracket, the arm detachably secured to one of the said trunnions andhaving l the rightangled sleeve, the drive-shaft journaled in saidsleeve, and the gear-wheel on said shaft, the feedscrew flattened onopposite sides, and the gear-wheel fitted on said screw and meshing withthe gear-Wheel on the drive shaft, substantially a's specified.

3. In a rock-drill, the combination of the bracket having a series ofopenings in the front 'edge of one side plate and a similar series inthe rear edge of the opposite side plate, and the pins H, arranged topass through corresponding openings in the two series, with thetrunnioned feedscrew sleeve and the arm detachably connected to thetrunnion, said sleeve and arm being engaged by the pins, substantiallyas specitied.

In testimony that we claim the foregoing as our own we have hereto afxedour signatures in presence of two witnesses.

NATHANIEL MILLER. JOHN RITCHIE. Witnesses:

WM. H. LAWLER, GEO. A. THOMAS.

